Chemistry is one of the chemicals, ionic compounds where the United ionic bonds ions in the structure of the formula of metal cations in general, positive ion and a polyatomic anion is the negatively charged

Tuesday, December 27, 2011

Ionic compounds are basically defined in such a way that compounds containing two or more ions are considered alongside electrical attraction. One of the positively charged ions (called "cations") and the second is a negative charge ("anion"). Cations are usually the metal atoms and anions are polyatomic ions or metals (ions with more than one atom). Thinking about school: the same thing that makes the positive and negative ends of the magnet attached to one another, which makes the cations and anions cling to each other.

Usually, when we are ionic compounds, forming large crystals, you can see with the naked eye. Table salt is an example of this - if you look at a salt crystal, it is likely that you will be able to see which looks a bit 'like a cube. This is because the salt as a stack of small cube-shaped.

Sometimes, when you see the salt, dust appears in place of the cube. This does not mean that salt is not a crystal - it means that the crystals are so small that you can not see with the naked eye. If you were to put the dust under a microscope, chances are you've seen a bit 'of geometric blocks.

So what are the important properties of salts? Well, I'm sure glad you asked ...

All ionic compounds form crystals. As far as I know, there are exceptions. Once again, the desire to form salt crystals, because when there is a whole series of small positive and negative electrical charges, all stuck together, seem to be happy bunch of small groups of stacking. The arrangement of these ions as part of a stack is different, and is called "unit cell". There are a dozen different types of cells generic units. When you graduate, you ask them. High school classes, it really is not so important.

Ionic compounds tend to have high melting and boiling points. When I say "high", which I think is "very, very high." Most of the time when working with ionic compounds in a chemistry class, the melting temperature is warm enough that you can not melt them with a Bunsen burner. So why such high temperatures? Well, it has to do with how the ionic materials are held together. Remember how we said earlier that crystals form ionic compounds? These crystals are really just great big blocks of positive and negative charges while being held. To break the positive and negative charges apart, it takes a tremendous amount of energy. This means that if we heat the fabric to add energy, it requires an enormous amount of energy to break.

Ionic compounds are very hard and very fragile. Again, it is because of how they stick together. Above we said that it takes a lot of energy to break the positive and negative charges apart. This is why ionic compounds are so difficult - it simply does not move much, so it does not bend at all. This also explains the fragility of the ionic compounds. It takes lots of energy for ionic charges of others. However, if we give a large crystal hit hard enough with a hammer, usually end up with more energy to break the glass the glass is not broken in one place, but a lot of places. Instead of cutting to the chase, is shattered.

Of electricity when ionic compounds dissolve in water. If we take salt and dissolved in water, the water molecules pull the positive and negative ions from each other. (This is due to the unusual properties of water, but it's a different story a different time). In contrast, the ions adjacent to each other, walking around in water. Now, think about what that power is - I hope you remember that electricity is only the movement of electrons through the metal (or elsewhere). Now, the electrons are the only negatively charged particles, and metals are the property of their own good, allowing them to go around. The salts are dissolved in the same way. When the salt dissolves in water, positive and negative ions in the water with the electrons to flow much better than if just had the water itself. Voila! The salt water does! The question is, maybe it is, "'the flow of electricity through crystals of salt?" Nope. It does not.

Because the ions are trapped in a place due to the crystal structure is electrically not move very well. Another good question: "Is the water without salt in the conduct electricity?" The answer: Not very well. The water itself is a lousy leader. The reason that sets hair in Boneheads the bath with them again in the donut man is that when they wash all the dirt on them will be dissolved in water. Some of ionic impurities, so when the dryer hit the water, they get zapped . A "thought experiment" It would be interesting to wash all the salt for yourself and then drop a hairdryer in the bath with you. In theory, you would be fine. In real life, would you still become a creature crunch because the tap water itself, there are ionic compounds dissolved in anyway.

When metals and non-metals chemically react, the atoms will tend to form ions or charged atoms. Ions form because electrons are either gained or lost. Metals will generally form cations or positive ions, since they tend to donateelectrons Non-metals will form anions or negative ions, since they tend to acceptelectrons.

Activity

In this activity you will create models of ionic compounds and observe the chemical formula of the binary molecules you have created. Your data will be recorded in a data table or chart, similar to the one below.

Cation name

Anion name

Chemical Formula

Name

Discussion/Conclusion (talk with your classmates and address in your write-up)

·Notice the shape and charge of each cation model. Why do you think there are slots in the metal atoms? (TIP: How do the atoms become ions?)

·Notice the shape and charge of the anion models. Why do you think there are tabs in the non-metal atoms?

·If you were to make a neutral atom following the model, what would the shape be?

·Group the ion models by family. What do you notice about the number of tabs or slots? What do you notice about the tabs or slots and charge of all ions? Is there a pattern? Why do you think the model is made that way?

·In the compounds you formed, what do you notice about the ion charges, the net or final charge of the compound and how the charge relates to the chemical formula of the compound?

·What do you notice about the names of the cations and anions on the cards. How do they compare with the name of the neutral atom or element. Do all metals have a number in parenthesis? Do the non-metals have anything in common about their name?

·Is there a pattern between elements in a group or family and any numbers on the Periodic Table? (TIP: Think octet rule and how many electrons are involved to meet octet.)

Data is organized into a table with the names of cation, anion, chemical formula and compound name.

Discussion and Conclusion addresses:

Explain how the model relates to the ion; number and shape of slot, (ie. charge, cation, anion), what a neutral atom would look like in the model.

Explain how elements are organized on the Periodic Table of Elements (i.e the category; metal or non-metal; and charge of the ion; amount of charge and position on the Periodic Table of Elements related to the valence electrons.

Explain the connection between the ion charge and the ratio of atoms in the chemical formula for the ionic compound (the pieces fit together to balance charge)

Identify the similarity in the name for all non-metal anions, similarity in the name for Alkai Metal and Alkaline Earth Metal cations; similarity in the name for all other metal cations.

3

Lab format follows the guidelines in the handout. Blank page on left for scores

Data does not have 40 combinations, cation name, anion name, charge chemical symbol, and chemical name

Missing some topics in the discussion or there is some incorrect information in parts of Discussion/Conclusion or data table.

2

Formatting problem

Conceptual errors when writing chemical formula or name of compounds

Missing or incorrect information in many parts of the Discussion/Conclusion

1

Major problems or conceptual errors.

Ionic Bonding Puzzle Lab Notes

The Model

Metals ___________ electrons and become positive ions or ______________.

Non-metals __________ electrons and become negative ions or _____________.

lose, cations, gain, anions

neutral atom ions

metal à

non-metal à

Using the same analogy for the atom, what would a +2 cation and a -2 anion look like?

Bonding and Predicting Chemical Formulas

Al2O3

The ______________ show the ___________ of each atom in the ________________.

subscripts, ratio, compound

For an ionic bond, the ________ need to balance _____________. The _____________ of each ion changes to make the compound _____________. The chemical ___________ shows how many of each ion are needed to _____________ the ____________ and make the compound neutral.

Ions, charge, number, neutral, formula, balance

What ratio will the +1 and -1 ions combine to balance the charge?

+ à

What ratio will the +2 and -1 ions combine to balance the charge?

+ à

Naming or Nomenclature

Use the name on the puzzle pieces to determine the name of each compound you created. TIP: In this lab if you create binary compounds you will save yourself time.

What do all of the Type II ions have in common?

What does the Roman Numeral show for a Type II ion?

Notice the Type ____ ions do not have a Roman Numeral. What are the charges of an ion formed from a Type I metal?

What do all ________ atomic non-metals or _______________ have in common?

mono-, anions

TIP: To make a subscript for a chemical formula, highlight the number and from the menu bar, select Format > Font > Subscript or A2 on the Font Formatting Pallette